Laser marking of ceramic materials, glazes, glass ceramics and glasses

Abstract

A method of laser marking ceramic materials, glazes, glass ceramics and glasses of any desired form, which comprises applying to the material to be marked a 100 to 10,000 Å thick transparent layer of titanium dioxide, then irradiating said oxide layer with a pulsed laser such that the radiation is directed onto said layer in accordance with the form of the marking to be applied, and using laser light of a wavelength which is sufficiently absorbed by the oxide layer, so that a discolouration of said oxide layer is produced at the irradiated areas.

What is claimed is: 
     
       1. A method of laser marking ceramic materials, glazes, glass ceramics and glasses of any desired form, which comprises applying to the material to be marked a 100 to 10,000 Å thick transparent layer of amorphous titanium dioxide, then irradiating said oxide layer with a pulsed laser such that the radiation is directed onto said layer in accordance with the form of the marking to be applied, and using laser light of a wavelength which is sufficiently absorbed by the oxide layer, so that a discolouration of said oxide layer is produced at the irradiated areas. 
     
     
       2. A method according to claim 1 of marking glass and glass ceramics. 
     
     
       3. A method according to claim 1, wherein the oxide layer has a thickness of 200 to 5000 Å. 
     
     
       4. A method according to claim 1, wherein the oxide layer is applied by treating the ceramic material with an organic titanium compound. 
     
     
       5. A method according to claim 4, wherein the organic titanium compound is a tetraalkoxy titanate or a titanium acetylacetonate. 
     
     
       6. A process according to claim 5, which comprises the use of a tetraalkoxy titanate containing 2 to 4 carbon atoms in each of the alkyl moieties. 
     
     
       7. A process according to claim 6, which comprises the use of titanium isopropylate. 
     
     
       8. A process according to claim 5, which comprises the use of diisopropoxy-bis(2,4-pentadionato)titanium(IV). 
     
     
       9. A process according to claim 1, which comprises the use of a laser whose wavelength is in the UV range. 
     
     
       10. A process according to claim 9, wherein the wavelength is in the range from 190 to 360 nm. 
     
     
       11. A process according to claim 1, which comprises the use of a pulsed or pulse-modified, frequency multiplied Nd:YAG laser or metal vapour laser, or an excimer laser. 
     
     
       12. A process according to claim 1, wherein irradiation is effected at a pulse content from 0.1 to 0.5 joule per cm 2  and a pulse duration of 5 to 40 nanoseconds. 
     
     
       13. A ceramic material, glaze, glass ceramic or glass laser marked by the process according to claim 1.